In the last years the field of electronic data processing has seen a rapid development. As a part of the development, more and more processes in enterprises or organizations have been automated. This includes processes that involve a participation of different partners or entities such as enterprises. Such processes can be described as collaborative processes. A description of a collaborative process at a business level is called a collaborative workflow. A collaborative workflow can be described by using a set of tasks that may be related to each other.
Participants in a collaborative workflow may have a supplier-customer relationship or may be competitors. Therefore, each participant of a collaborative workflow may have certain conditions for participating in the collaborative workflow. The conditions may relate for example to keeping certain internal process details private or to complying with general security requirements.